Hello my name is ***** ***** I will help you.
Why wasn't anything signed or in writing please?
Do you not have emails or anything confirming the agreement?
but they agreed by email to the deal?
Ok. Agreements can either be in writing or verbal.
Here you have a verbal agreement followed by actions of payment - this indicates a contract.
Therefore even if nothing was in writing you have paid monthly and therefore this indicates the verbal contract, otherwise why wish you pay?
Therefore you don't have to let them back - you have a verbal contract and payments made.
In any event your accountant can confirm it was agreed - they have no right to come back.
Can I clairfy anything for you about this today please?
If I could invite you to rate my answer before you go today please, otherwise the site does not credit me for the time spent with you today. Thanks and good luck. Alex